Hotshoe flashes with built in lithium ion battery/charger. Why doesn't this exist?

Flash technology has aged really slow since the 1980s. I've noticed almost every one of my electronic devices I own have some sort of built in battery with charger. I made the upgrade from Nicad electric shaver to lithium ion, holy cow the difference is phenomenal. My cordless power tools got the lithium treatment as well.

I don't use flash enough to worry about it, but in general I prefer batteries that are removable for most things. No rechargeable will recharge as fast as switching to a second set if you run out in the middle of something! As to lithium ion, a lot of the small custom battery packs are quite pricey (ref: Canon BP511A and NB10L), I assume built-ins would have a similar problem, adding cost to the package. Plus what happens when the built-in battery dies -- they do, and in fact some seem to fade after two or three years.

I hate units with built in Lithium batteries. I tolerate it on my GPS unit in my car, as I don't really expect to use it for any extended period as a pedestrian. I tolerate it in my smartphone because after the built in battery ages a few years, I will most likely simply get a new smartphone from my wireless vendor at a significant discount!

But I would hate to think that a speedlight goes useless after three years because the capacity of the lithium anode has deteriorated and lost capacity (lithium begins to age as soon as it is manufactured!!!)

Personally, I doubt if there is the "market" to really make it worth it from the manufacturer's position. Look how many more iPhones there are versus any model of camera flash. Dave's point about not using flash frequently also cements the notion of this: what manufacturer want's to make a state-of-the-art flash with all the bells and whistles with all the newest battery technology only to have the batteries go bad due to lack of proper care and feeding by the user? That manufacturer get's the blame for producing the most horrible flash ever made.......better to let the user screw with battery care, and not have Nikon or Canon blamed......

Those of us nursing Metz flashes of old with the old Ni-cd rechargeables know about battery care and nursing......rechargeable batteries of any technology do require care.....some more than others. There are some wonderful types of newer batteries out there that could almost live through our infrequent flash usage, but cost would be or could be significant so our camera manufactures will never consider producing them. So we are stuck with AA's for a long, long time.

First, the internal battery would degrade over some years and then you have a useless flash. All my current flashes are at least 20-30 years old and are running fine with modern rechargeable AA and AAA batteries. Also, the nice thing about using replaceable batteries is you can take advantage of new technology as batteries improve instead of being stuck with what is in your flash.

Also, what if you drain the battery while shooting or accidentally leave the flash on and it's dead when you want to shoot? What do you do? You can't just swap in fresh batteries and start shooting. You have to plug it in and wait for it to charge.